US4649201A - Removal of ferric chloride from halopyridines - Google Patents
Removal of ferric chloride from halopyridines Download PDFInfo
- Publication number
- US4649201A US4649201A US06/813,905 US81390585A US4649201A US 4649201 A US4649201 A US 4649201A US 81390585 A US81390585 A US 81390585A US 4649201 A US4649201 A US 4649201A
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- United States
- Prior art keywords
- pyridine
- halopyridine
- ferric chloride
- dichloro
- trichloromethyl
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D211/00—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings
- C07D211/04—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D211/06—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members
- C07D211/36—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D211/38—Halogen atoms or nitro radicals
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D213/61—Halogen atoms or nitro radicals
Definitions
- ferric chloride is a catalyst for the preparation of 2,3,5,6-tetrachloropyridine by chlorination of 2,6-dichloro-pyridine (U.S. Pat. No. 3,538,100), 3,5-dichloro-pyridine (U.S. Pat. No. 4,225,718), or 2-chloro-6-(trichloromethyl)pyridine (U.S. Pat. No.
- ferric chloride is commonly present as an undesirable corrosion product in such reactions. This ferric chloride must generally be removed from the halopyridine in a purification procedure before the halopyridine can be sold or utilized as an intermediate for the preparation of other useful products.
- Ferric chloride is conventionally removed from halopyridine and other halogenated compound mixtures containing it by distillation, which leaves the ferric chloride as a non-distillable residue, or by dissolving the halogenated compound in a chlorinated hydrocarbon solvent, which leaves the ferric chloride as a solid that can be separated by filtration.
- Neither of these methods is very efficient and their utility in commercial operations is limited. This is because halopyridines appear to bond to ferric chloride in some manner and this bonding results not only in a high apparent solubility of ferric chloride in halopyridines, but also in a difficulty in separating them.
- ferric chloride can be extracted from its mixtures with halopyridines using certain immiscible diol solvents. Ferric chloride is soluble in these diol solvents and is removed from the mixture as a solution in them, leaving the essentially ferric chloride free halopyridine as a residue.
- An important additional benefit of the process is that much of the by-product tarry material often present in halopyridine reaction mixtures is extracted from the desired halopyridines as well.
- the ferric chloride removal process of the present invention is effected by admixing a liquid mixture containing ferric chloride and at least one halopyridine compound of the formula ##STR1## wherein each X, independently, represents chlorine or fluorine,
- n an integer of 1 to 5
- n represents an integer of 0 to 2 with the proviso that the sum of m and n is an integer of 2 to 5,
- p represents an integer of 1 or 2
- q represents an integer of 1 to 4,
- the process of the present invention has been found to be very efficient. Up to 99 percent recovery of halopyridines, which originally contained up to 20 percent ferric chloride and after extraction contained less than one percent, has been achieved.
- the halopyridines extracted using the process of the present invention generally contain less than 0.5 percent residual diol solvent. They can be used directly for many applications; can be further purified by conventional techniques, such as distillation or crystallization; or can be recycled back into the process from which they were derived.
- the purified halopyridines of the present invention are useful herbicides and nitrification inhibitors and are useful intermediates for the production of insecticides, fungicides and herbicides.
- halopyridines which can be present in the halopyridine-ferric chloride mixtures of the invention include pentachloropyridine; 2,3,4,5-, 2,3,4,6-, and 2,3,5,6-tetrachloropyridine; 2,3,5-, and 2,3,6-trichloropyridine, 3,5-dichloro-2,4,6-trifluoropyridine; 3,5-dichloro-2,6-difluoropyridine; tetrachloro-4-(trichloromethyl)pyridine; 2,3,6-trichloro-4-(trichloromethyl)pyridine; 2,6-dichloro-4-(trifluoromethyl)pyridine; tetrachloro-3-(trichloromethyl)pyridine; 2,3,
- Diols that are essentially immiscible with the extracted halopyridine containing composition and in which ferric chloride is soluble to some degree are useful solvents in the process.
- useful diol solvents include ethylene glycol; propylene glycol; 1,3-propanediol; mono-, di-, tri-, and tetraethylene glycol; mono-, di-, tri-, and tetrapropylene glycol. Ethylene glycol and propylene glycol are preferred.
- the diols employed are generally items of commerce.
- ferric chloride-halopyridine mixtures of the invention be in the liquid state during the extraction operation of the process. Suspended solids may, however, be present. Many such mixtures are liquid at ambient temperatures and can be extracted at these or at elevated temperatures. Solid or semisolid mixtures can be liquified before the extraction operation by heating to temperatures up to 150° C. and/or by the addition of chlorinated hydrocarbon solvents such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethylene, or tetrachloroethylene. It is preferred to carry out the extraction at temperatures below 130° C. and more preferred below 45° C. If a chlorinated hydrocarbon solvent is added, it is preferred to use as little as possible to effect liquification at the temperature of the extraction.
- chlorinated hydrocarbon solvents such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichlor
- the ratio of diol solvent to ferric chloride-halopyridine mixture used in the process varies depending on the amount of ferric chloride present, the specific halopyridines present, and the specific diol solvent employed.
- the process works well with excess diol solvent, but it is economically advantageous to minimize its amount. This minimum amount is sometimes less than the theoretical minimum calculated based on the solubility of ferric chloride in the diol solvent; i.e., ferric chloride is often more soluble in a diol solvent containing materials extracted from the mixture than in pure diol solvent.
- Ratios of diol solvent to ferric chloride-halopyridine mixture of from about 10 to 1 to about 1 to 50 are usefully employed for mixtures containing about 1 to about 30 percent ferric chloride. Ratios of about 5 to 1 to about 1 to 10 are usually employed.
- the process of the invention can be carried out either batchwise or in a continuous manner.
- any vessel equipped with means for adding the halopyridine-ferric chloride mixture and the diol solvent, agitating, heating (if required), and separating the phases can be employed.
- a counter current flow liquid-liquid column extractor having means for introducing the halopyridine-ferric chloride mixture at the top and removing it at the bottom and means for introducing the immiscible diol solvent at the bottom and removing it at the top, is typically employed. In either system the two phases must be thoroughly mixed to obtain optimal removal of the ferric chloride.
- a 19.2 g sample of a mixture having the composition shown in the table below was combined with 27.8 g of ethylene glycol in a jar.
- the admixture was heated to 125° C. and manually shaken on about 15 minute intervals for about 100 minutes.
- the phases were allowed to separate and the upper ethylene glycol phase was removed with a pipette.
- the lower phase containing the halopyridines weighed 17.6 g and was found to have the composition shown in the table below.
- the lower halopyridine phase which was an estimated 7.8 g, contained about 96 percent volatile chloropyridines including 3,5,6-trichloro-2-(trichloromethyl)pyridine, any residual ethylene glycol, about 1 percent ferric chloride, and about 3.3 percent non-volatile tars.
- Ethylene glycol (94 parts) was placed in a reaction vessel and a ferric chloride-halopyridine mixture (240 parts) which had been heated to 85° C. was added. The admixture was agitated and allowed to cool to about 52° C. over a 1 hour period. The phases were allowed to separate and cool to 45° C. and the lower halopyridine phase was then removed through a bottom drain. It amounted to 162 parts. Analyses of the ferric chloride-halopyridine mixture before and after extraction is shown in the table below.
- the ferric chloride reduction was about 92 percent and the halopyridine recovery about 90 percent.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pyridine Compounds (AREA)
Abstract
Ferric chloride is removed from mixtures with chlorinated and/or fluorinated pyridines and methylpyridines by extraction with diol solvents. For example, the ferric chloride in halopyridine mixtures containing 2,3,5,6-tetrachloropyridine was removed by extraction with ethylene glycol. The purified halopyridines are useful intermediates for the production of insecticides, herbicides, and fungicides.
Description
The use of ferric chloride as a catalyst in chlorination and fluoride-chloride exchange reactions involving halopyridines is well known and ferric chloride is a common component of reaction mixtures obtained in the manufacture of halopyridines. For example, ferric chloride is a catalyst for the preparation of 2,3,5,6-tetrachloropyridine by chlorination of 2,6-dichloro-pyridine (U.S. Pat. No. 3,538,100), 3,5-dichloro-pyridine (U.S. Pat. No. 4,225,718), or 2-chloro-6-(trichloromethyl)pyridine (U.S. Pat. No. 4,256,894); the preparation of 2,3-dichloro-6-(trichloromethyl)-pyridine by chlorination of 2-chloro-6-(trichloromethyl)-pyridine (U.S. Pat. No. 4,256,894); the preparation of 3,5-dichloro-2,4,6-trifluoropyridine by halogen exchange of pentachloropyridine (U.S. Pat. No. 4,542,221) and the preparation of 2,3-dichloro-5-(trifluoromethyl)-pyridine by halogen exchange of 2,3-dichloro-5-(tri-chloromethyl)pyridine (EPO Application No. 83307212.7) or 2-fluoro-3-chloro-5-(trifluoromethyl)pyridine (U.S. Pat. No. 4,546,192). Additionally, ferric chloride is commonly present as an undesirable corrosion product in such reactions. This ferric chloride must generally be removed from the halopyridine in a purification procedure before the halopyridine can be sold or utilized as an intermediate for the preparation of other useful products.
Ferric chloride is conventionally removed from halopyridine and other halogenated compound mixtures containing it by distillation, which leaves the ferric chloride as a non-distillable residue, or by dissolving the halogenated compound in a chlorinated hydrocarbon solvent, which leaves the ferric chloride as a solid that can be separated by filtration. Neither of these methods is very efficient and their utility in commercial operations is limited. This is because halopyridines appear to bond to ferric chloride in some manner and this bonding results not only in a high apparent solubility of ferric chloride in halopyridines, but also in a difficulty in separating them. Thus, even though it is possible and often desirable to isolate the bulk of a halopyridine from a mixture by distillation, distillation alone is not efficient because after completion of the distillation much of the halopyridine remains in the residue with the ferric chloride and cannot be separated from the ferric chloride by further distillation. Heating to higher temperatures causes decomposition of halopyridines and is therefore wasteful and dangerous. Extraction of ferric chloride contaminated halopyridines with chlorinated hydrocarbon solvents is also not efficient as that portion of the halopyridine bound to ferric chloride is not extracted. Additionally, the chlorinated hydrocarbon solvent employed must be removed from the halopyridine in a subsequent operation. This situation and the high value of many halopyridines makes it desirable to have improved methods of separating ferric chloride from halopyridines.
It has now been found that ferric chloride can be extracted from its mixtures with halopyridines using certain immiscible diol solvents. Ferric chloride is soluble in these diol solvents and is removed from the mixture as a solution in them, leaving the essentially ferric chloride free halopyridine as a residue. An important additional benefit of the process is that much of the by-product tarry material often present in halopyridine reaction mixtures is extracted from the desired halopyridines as well.
The ferric chloride removal process of the present invention is effected by admixing a liquid mixture containing ferric chloride and at least one halopyridine compound of the formula ##STR1## wherein each X, independently, represents chlorine or fluorine,
m represents an integer of 1 to 5, and
n represents an integer of 0 to 2 with the proviso that the sum of m and n is an integer of 2 to 5,
with an immiscible diol solvent of the formula ##STR2## wherein R represents hydrogen or methyl,
p represents an integer of 1 or 2, and
q represents an integer of 1 to 4,
allowing the admixture to separate into halopyridine and diol solvent phases; and, thereafter, removing the diol phase from the halopyridine phase.
The process of the present invention has been found to be very efficient. Up to 99 percent recovery of halopyridines, which originally contained up to 20 percent ferric chloride and after extraction contained less than one percent, has been achieved. The halopyridines extracted using the process of the present invention generally contain less than 0.5 percent residual diol solvent. They can be used directly for many applications; can be further purified by conventional techniques, such as distillation or crystallization; or can be recycled back into the process from which they were derived.
The purified halopyridines of the present invention are useful herbicides and nitrification inhibitors and are useful intermediates for the production of insecticides, fungicides and herbicides.
The present process works well for halopyridine mixtures with ferric chloride that contain either predominantly a single halopyridine specie or a composite of halopyridine species, none of which is predominant. The mixtures may also contain other components. Examples of halopyridines which can be present in the halopyridine-ferric chloride mixtures of the invention include pentachloropyridine; 2,3,4,5-, 2,3,4,6-, and 2,3,5,6-tetrachloropyridine; 2,3,5-, and 2,3,6-trichloropyridine, 3,5-dichloro-2,4,6-trifluoropyridine; 3,5-dichloro-2,6-difluoropyridine; tetrachloro-4-(trichloromethyl)pyridine; 2,3,6-trichloro-4-(trichloromethyl)pyridine; 2,6-dichloro-4-(trifluoromethyl)pyridine; tetrachloro-3-(trichloromethyl)pyridine; 2,3,6-trichloro-5-(trichloromethyl)pyridine; 2,3- and 2,6-dichloro-5-(trichloromethyl)pyridine; 2-chloro-5-(trichloromethyl)pyridine; 2,3- and 2,6-dichloro-5-(trifluoromethyl)pyridine; 2,3- and 2,6-dichloro-5-(chlorodifluoromethyl)pyridine; 2-chloro-5-(dichlorofluoromethyl)pyridine, 2-chloro-5-(trifluoromethyl)pyridine; 2-chloro-3-fluoro-5-(trifluoromethyl)pyridine; 3-chloro-2-fluoro-5-(chlorodifluoromethyl)pyridine; 2-fluoro-5-(chlorodifluoromethyl)pyridine; 2,3-difluoro-5-(trifluoromethyl) pyridine; tetrachloro-2-(trichloromethyl)pyridine; 3,4,5- and 3,5,6-trichloro-2-(trichloromethyl)pyridine; 5,6- and 3,6-dichloro-2-(trichloromethyl)pyridine; 3,6-dichloro-2-(trifluoromethyl)pyridine; 3-chloro-2 -fluoro-6-(chlorodifluoromethyl)pyridine; 2-chloro-6-(trichloromethyl)pyridine; 2-fluoro-6-(dichlorofluoromethyl)pyridine; 2-chloro-3,5-bis(trichloromethyl)pyridine; 2,6-dichloro-3,5-bis(trichloromethyl)pyridine and 2-chloro-3,5-bis(trifluoromethyl)pyridine. Such compounds and their methods of preparation are well known in the art.
Diols that are essentially immiscible with the extracted halopyridine containing composition and in which ferric chloride is soluble to some degree are useful solvents in the process. Examples of useful diol solvents include ethylene glycol; propylene glycol; 1,3-propanediol; mono-, di-, tri-, and tetraethylene glycol; mono-, di-, tri-, and tetrapropylene glycol. Ethylene glycol and propylene glycol are preferred. The diols employed are generally items of commerce.
It is essential that the ferric chloride-halopyridine mixtures of the invention be in the liquid state during the extraction operation of the process. Suspended solids may, however, be present. Many such mixtures are liquid at ambient temperatures and can be extracted at these or at elevated temperatures. Solid or semisolid mixtures can be liquified before the extraction operation by heating to temperatures up to 150° C. and/or by the addition of chlorinated hydrocarbon solvents such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethylene, or tetrachloroethylene. It is preferred to carry out the extraction at temperatures below 130° C. and more preferred below 45° C. If a chlorinated hydrocarbon solvent is added, it is preferred to use as little as possible to effect liquification at the temperature of the extraction.
The ratio of diol solvent to ferric chloride-halopyridine mixture used in the process varies depending on the amount of ferric chloride present, the specific halopyridines present, and the specific diol solvent employed. The process works well with excess diol solvent, but it is economically advantageous to minimize its amount. This minimum amount is sometimes less than the theoretical minimum calculated based on the solubility of ferric chloride in the diol solvent; i.e., ferric chloride is often more soluble in a diol solvent containing materials extracted from the mixture than in pure diol solvent. Ratios of diol solvent to ferric chloride-halopyridine mixture of from about 10 to 1 to about 1 to 50 are usefully employed for mixtures containing about 1 to about 30 percent ferric chloride. Ratios of about 5 to 1 to about 1 to 10 are usually employed.
The process of the invention can be carried out either batchwise or in a continuous manner. For batch operations any vessel equipped with means for adding the halopyridine-ferric chloride mixture and the diol solvent, agitating, heating (if required), and separating the phases can be employed. For continuous operations a counter current flow liquid-liquid column extractor having means for introducing the halopyridine-ferric chloride mixture at the top and removing it at the bottom and means for introducing the immiscible diol solvent at the bottom and removing it at the top, is typically employed. In either system the two phases must be thoroughly mixed to obtain optimal removal of the ferric chloride.
The following examples are merely illustrations of the present invention and should not be construed as limiting.
A 19.2 g sample of a mixture having the composition shown in the table below was combined with 27.8 g of ethylene glycol in a jar. The admixture was heated to 125° C. and manually shaken on about 15 minute intervals for about 100 minutes. The phases were allowed to separate and the upper ethylene glycol phase was removed with a pipette. The lower phase containing the halopyridines weighed 17.6 g and was found to have the composition shown in the table below.
______________________________________
Initial Final
Mixture Component Conc., % Conc., %
______________________________________
2,3,5,6-tetrachloropyridine
61.6 65.5
pentachloropyridine
15.9 17.4
other identifiable
12.9 14.9
chloropyridines
Total chloropyridines
90.4 97.8
ferric chloride 1.6 <0.4
other non-volatiles
1.2 not detectable
ethylene glycol -- not detectable
______________________________________
Thus, by this analysis, there was over 75 percent reduction in the ferric chloride content with a loss of only about 1 percent of the total chloropyridines.
An 8.56 g sample of a mixture containing 87.4 percent volatile chloropyridines including 3,5,6-trichloro-2-(trichloromethyl)pyridine, 2.2 percent ferric chloride, and 10.4 percent non-volatile tars was combined with 9.91 g of ethylene glycol in a jar at 22° C. The admixture was shaken manually every 15 minutes for several hours and then allowed to separate into phases, both of which were very dark. The top ethylene glycol phase was removed as well as possible with a pipette. The lower halopyridine phase, which was an estimated 7.8 g, contained about 96 percent volatile chloropyridines including 3,5,6-trichloro-2-(trichloromethyl)pyridine, any residual ethylene glycol, about 1 percent ferric chloride, and about 3.3 percent non-volatile tars.
Ethylene glycol (94 parts) was placed in a reaction vessel and a ferric chloride-halopyridine mixture (240 parts) which had been heated to 85° C. was added. The admixture was agitated and allowed to cool to about 52° C. over a 1 hour period. The phases were allowed to separate and cool to 45° C. and the lower halopyridine phase was then removed through a bottom drain. It amounted to 162 parts. Analyses of the ferric chloride-halopyridine mixture before and after extraction is shown in the table below.
______________________________________
Initial Final
Mixture Component Conc., % Conc., %
______________________________________
2,3-dichloro-5-(trichloro-
14.9 24.1
methyl)pyridine
2,3-dichloro-5-(chlorodi-
9.6 13.4
fluoromethyl)pyridine*
2,3-dichloro-5-(dichloro-
14.0 23.6
fluoromethyl)pyridine*
2,3-dichloro-5-(trifluoro-
11.5 21.0
methyl)pyridine*
other volatile halopyridines
5.3 9.1
Total halopyridines
55.3 91.2
ferric chloride 20.1 1.6
ethylene glycol -- 0.3
______________________________________
*may include isomers
The ferric chloride reduction was about 92 percent and the halopyridine recovery about 90 percent.
Claims (16)
1. A process for extracting ferric chloride from mixtures comprising ferric chloride and at least one halopyridine compound of the formula ##STR3## wherein each X, independently, represents Cl or F,
m represents an integer of 1 to 5, and
n represents an integer of 0 to 2 with the proviso that the sum of m and n is an integer of 2 to 5,
which comprises: admixing the halopyridine as a liquid with an essentially immiscible diol solvent of the formula ##STR4## wherein R represents hydrogen or methyl,
p represents an integer of 1 or 2, and
q represents an integer of 1 to 4;
allowing the admixture to separate into halopyridine and diol solvent phases; and, thereafter, removing the diol solvent phase from the halopyridine phase.
2. A process of claim 1 wherein the diol solvent is ethylene glycol.
3. A process of claim 1 wherein the diol solvent is propylene glycol.
4. A process of claim 1 wherein the extraction is conducted batchwise.
5. A process of claim 1 wherein the extraction is conducted in a continuous manner.
6. A process of claim 1 wherein the mixture is made liquid by heating.
7. A process of claim 1 wherein the mixture is made liquid by the addition of a chlorinated hydrocarbon solvent.
8. A process of claim 1 wherein the halopyridine compound is 2,3,5,6-tetrachloropyridine.
9. A process of claim 1 wherein the halopyridine compound is 3,5-dichloro-2,6-difluoropyridine.
10. A process of claim 1 wherein the halopyridine compound is 2,3-dichloro-5-(trichloromethyl)pyridine.
11. A process of claim 1 wherein the halopyridine compound is 2,3-dichloro-5-(chlorodifluoromethyl)pyridine or 2-fluoro-3-chloro-5-(dichlorofluoromethyl)pyridine.
12. A process of claim 1 wherein the halopyridine compound is 2,3-dichloro-5-(trifluoromethyl)pyridine.
13. A process of claim 1 wherein the halopyridine compound is 2-chloro-5-(trifluoromethyl)pyridine.
14. A process of claim 1 wherein the halopyridine compound is 2,3-difluoro-5-(trifluoromethyl)pyridine.
15. A process of claim 1 wherein the halopyridine compound is 3,6-dichloro-2-(trichloromethyl)pyridine.
16. A process of claim 1 wherein the halopyridine compound is 2,3,5-trichloro-6-(trichloromethyl)pyridine.
Priority Applications (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/813,905 US4649201A (en) | 1985-12-27 | 1985-12-27 | Removal of ferric chloride from halopyridines |
| IL80777A IL80777A (en) | 1985-12-27 | 1986-11-26 | Removal of ferric chloride from halopyridines |
| CA000523954A CA1264756A (en) | 1985-12-27 | 1986-11-27 | Removal of ferric chloride from halopyridines |
| AU65815/86A AU589471B2 (en) | 1985-12-27 | 1986-11-28 | Removal of ferric chloride from halopyridines |
| EP86117462A EP0228643A3 (en) | 1985-12-27 | 1986-12-16 | Removal of ferric chloride from halopyridines |
| JP61299818A JPS62167766A (en) | 1985-12-27 | 1986-12-16 | Removal of ferric chloride from halopyridine |
| BR8606573A BR8606573A (en) | 1985-12-27 | 1986-12-19 | REMOVAL OF HALOPYRIDINE FERRIC CHLORIDE |
| HU865416A HU198850B (en) | 1985-12-27 | 1986-12-23 | Process for removing ferric chloride-iii from halogenized pyridines |
| CN198686108662A CN86108662A (en) | 1985-12-27 | 1986-12-26 | From Halogenated Pyridine Compounds, remove iron(ic) chloride |
| KR1019860011266A KR890003837B1 (en) | 1985-12-27 | 1986-12-26 | How to remove ferric chloride from halopyridine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/813,905 US4649201A (en) | 1985-12-27 | 1985-12-27 | Removal of ferric chloride from halopyridines |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US4649201A true US4649201A (en) | 1987-03-10 |
Family
ID=25213720
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US06/813,905 Expired - Fee Related US4649201A (en) | 1985-12-27 | 1985-12-27 | Removal of ferric chloride from halopyridines |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US4649201A (en) |
| EP (1) | EP0228643A3 (en) |
| JP (1) | JPS62167766A (en) |
| KR (1) | KR890003837B1 (en) |
| CN (1) | CN86108662A (en) |
| AU (1) | AU589471B2 (en) |
| BR (1) | BR8606573A (en) |
| CA (1) | CA1264756A (en) |
| HU (1) | HU198850B (en) |
| IL (1) | IL80777A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4827060A (en) * | 1987-11-09 | 1989-05-02 | The Dow Chemical Company | Removal and recycling of catalysts in chlorinated pricess streams |
| US10882824B2 (en) * | 2017-04-04 | 2021-01-05 | Ishihara Sangyo Kaisha, Ltd. | Method for purifying trifluoromethylpyridines |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3538100A (en) * | 1968-03-15 | 1970-11-03 | Olin Corp | Process for preparing highly chlorinated pyridines |
| US4225718A (en) * | 1979-02-22 | 1980-09-30 | The Dow Chemical Company | Process for recovering 2,3,5,6-tetrachloropyridine |
| US4256894A (en) * | 1978-04-24 | 1981-03-17 | The Dow Chemical Company | Preparation of chlorinated pyridines |
| EP0110690A1 (en) * | 1982-11-26 | 1984-06-13 | The Dow Chemical Company | Preparation of (trifluoromethyl)pyridines |
| US4542221A (en) * | 1981-05-18 | 1985-09-17 | The Dow Chemical Company | Exchanging fluorine for chlorine in a chlorinated pyridine with an alkali metal fluoride |
| US4546192A (en) * | 1982-09-23 | 1985-10-08 | The Dow Chemical Company | Chlorine exchange for fluorine in ring-fluorinated pyridine compounds |
-
1985
- 1985-12-27 US US06/813,905 patent/US4649201A/en not_active Expired - Fee Related
-
1986
- 1986-11-26 IL IL80777A patent/IL80777A/en unknown
- 1986-11-27 CA CA000523954A patent/CA1264756A/en not_active Expired - Fee Related
- 1986-11-28 AU AU65815/86A patent/AU589471B2/en not_active Ceased
- 1986-12-16 EP EP86117462A patent/EP0228643A3/en not_active Ceased
- 1986-12-16 JP JP61299818A patent/JPS62167766A/en active Pending
- 1986-12-19 BR BR8606573A patent/BR8606573A/en unknown
- 1986-12-23 HU HU865416A patent/HU198850B/en not_active IP Right Cessation
- 1986-12-26 KR KR1019860011266A patent/KR890003837B1/en not_active IP Right Cessation
- 1986-12-26 CN CN198686108662A patent/CN86108662A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3538100A (en) * | 1968-03-15 | 1970-11-03 | Olin Corp | Process for preparing highly chlorinated pyridines |
| US4256894A (en) * | 1978-04-24 | 1981-03-17 | The Dow Chemical Company | Preparation of chlorinated pyridines |
| US4225718A (en) * | 1979-02-22 | 1980-09-30 | The Dow Chemical Company | Process for recovering 2,3,5,6-tetrachloropyridine |
| US4542221A (en) * | 1981-05-18 | 1985-09-17 | The Dow Chemical Company | Exchanging fluorine for chlorine in a chlorinated pyridine with an alkali metal fluoride |
| US4546192A (en) * | 1982-09-23 | 1985-10-08 | The Dow Chemical Company | Chlorine exchange for fluorine in ring-fluorinated pyridine compounds |
| EP0110690A1 (en) * | 1982-11-26 | 1984-06-13 | The Dow Chemical Company | Preparation of (trifluoromethyl)pyridines |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4827060A (en) * | 1987-11-09 | 1989-05-02 | The Dow Chemical Company | Removal and recycling of catalysts in chlorinated pricess streams |
| US10882824B2 (en) * | 2017-04-04 | 2021-01-05 | Ishihara Sangyo Kaisha, Ltd. | Method for purifying trifluoromethylpyridines |
Also Published As
| Publication number | Publication date |
|---|---|
| CA1264756A (en) | 1990-01-23 |
| KR870005992A (en) | 1987-07-08 |
| KR890003837B1 (en) | 1989-10-05 |
| AU6581586A (en) | 1987-07-02 |
| HUT43961A (en) | 1988-01-28 |
| HU198850B (en) | 1989-12-28 |
| BR8606573A (en) | 1987-10-20 |
| EP0228643A3 (en) | 1988-10-05 |
| EP0228643A2 (en) | 1987-07-15 |
| IL80777A0 (en) | 1987-02-27 |
| CN86108662A (en) | 1987-09-09 |
| IL80777A (en) | 1990-09-17 |
| AU589471B2 (en) | 1989-10-12 |
| JPS62167766A (en) | 1987-07-24 |
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